The purpose of this study is to determine if exercise stimulates a GH response in obese women compared to non-obese women and if aerobic exercise training alters the GH response to exercise. 8 non-obese women, 10 LBO and 10 UBO women will be assessed with 1) a 6 h GH profile (q5 blood sampling), 2) percent body fat, 3) cardiovascular fitness, 4) blood lipids and 5) resting metabolic rate. The 20 obese women will undergo 16 weeks of aerobic training at 3 times/wk.